English
Related papers

Related papers: Early Galactic Li, Be and B: Implications on Cosmi…

200 papers

Galactic cosmic rays are believed to be accelerated at supernova remnant shocks. Gamma-ray observations of both supernova remnants and associated molecular clouds have been used in several occasions to test (so far quite successfully) this…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Stefano Gabici

The apparent absence of stars in the Milky Way halo with -5 ~< [Fe/H] ~< -4 suggests that the gas out of which the halo stars were born experienced a period of low or delayed star formation after the local universe was lit up by the first,…

Astrophysics · Physics 2009-11-11 Torgny Karlsson

We reassess the problem of the production and evolution of the light elements Li, Be and B and of their isotopes in the Milky Way, in the light of new observational and theoretical developments. The main novelty is the introduction of a new…

Astrophysics of Galaxies · Physics 2015-06-04 N. Prantzos

We discuss the production of the element $^6$Li in the early Galaxy by cosmic rays accelerated at structure formation shocks, driven by the hierarchical merging of sub-Galactic halos during Galaxy formation. The salient features of this…

Astrophysics · Physics 2009-11-07 Susumu Inoue , Takeru Ken Suzuki

Recently models based on the acceleration of metal-rich material inside superbubbles have been proposed to account for the observed abundances of Be and B in metal-poor halo stars. We analyse some of the implications of these models for the…

Astrophysics · Physics 2007-05-23 E. Parizot , L. Drury

The origin of cosmic rays from outside the Solar system are unknown, as they are deflected by the interstellar magnetic field. Supernova remnants are the main candidate for cosmic rays up to PeV energies but due to lack of evidence, they…

High Energy Astrophysical Phenomena · Physics 2026-01-13 Nicolas J. Bacon , Alex J. Cooper , Dimitrios Kantzas , James H. Matthews , Rob Fender

Supernova remnants (SNRs) have long been considered to be the dominant source of Galactic cosmic rays, which implied that they provided most of the energy to power cosmic rays as well as being PeVatrons. The lack of evidence for PeV cosmic…

High Energy Astrophysical Phenomena · Physics 2022-12-27 Jacco Vink

In 1990's Very High Energy Gamma-ray Astrophysics has dramatically advanced due to the Imaging Air \v{C}erenkov Telescopes(IACTs). After the first detection of TeV gamma-ray emission from the Crab nebula in 1989, several type of TeV…

Astrophysics · Physics 2009-11-07 Toru Tanimori

The composition of Galactic Cosmic Rays (GCR) presents strong similarities to the standard (cosmic) composition, but also noticeable differences, the most important being the high isotopic ratio of Ne22/Ne20 which is about 5 times higher in…

High Energy Astrophysical Phenomena · Physics 2015-06-03 N. Prantzos

Although Galactic cosmic rays (protons and nuclei) are widely believed to be dominantly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery [1].…

This is the first of a series of papers analysing the Galactic Cosmic Ray composition and origin. We show that the Galactic Cosmic Ray source (GCRS) composition is best described in terms of (i) a general enhancement of the refractory…

Astrophysics · Physics 2009-10-30 Jean-Paul Meyer , L. O'C. Drury , Donald C. Ellison

Most cosmic rays are thought to be accelerated by the shocks of supernova explosions of very massive stars. Here we review one quantitative proposal, which predicted the spectral slopes, bend and cutoff about the cosmic ray spectrum across…

Astrophysics · Physics 2009-11-10 Peter L. Biermann

One century ago Viktor Hess carried out several balloon flights that led him to conclude that the penetrating radiation responsible for the discharge of electroscopes was of extraterrestrial origin. One century from the discovery of this…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Pasquale Blasi

Spallative nucleosynthesis is thought to be the only process capable of producing significant amount of Beryllium (Be) in the universe. Therefore, both energetic particles (EPs) and nuclei to be spalled (most efficiently C, N and O nuclei…

Astrophysics · Physics 2016-08-30 Etienne Parizot , Luke Drury

Oxygen is a much better evolutionary index than iron to follow the history of Lithium-Beryllium-Boron (LiBeB) since it is the main producer of these light elements at least in the early Galaxy. The O-Fe relation is crucial to the…

Astrophysics · Physics 2007-05-23 Elisabeth Vangioni-Flam , Michel Casse

The cosmic star formation histories are evaluated for different minimum masses of the initial halo structures, with allowance for realistic gas outflows. With a minimum halo mass of 10^{7} - 10^{8} M_odot and a moderate outflow efficiency,…

Astrophysics · Physics 2009-09-15 Frederic Daigne , Keith A. Olive , Joe Silk , Felix Stoehr , Elisabeth Vangioni

The rate of ionization by cosmic rays in interstellar gas directly associated with gamma-ray emitting supernova remnants is for the first time calculated to be several orders of magnitude larger than the Galactic average. Analysis of…

Astrophysics of Galaxies · Physics 2015-05-28 J. K. Becker , J. H. Black , M. Safarzadeh , F. Schuppan

Employing a Monte-Carlo based evolutionary code, we show that the delay of Fe deposition relative to O, due to the incorporation of supernova ejecta refractories in high velocity grains, can account for the rise of [O/Fe] with decreasing…

Astrophysics · Physics 2007-05-23 R. Ramaty , B. Kozlovsky , R. E. Lingenfelter

In a companion paper, we investigated the question of the spatial origin of the cosmic rays detected in the Solar neighborhood, in the case of standard sources located in the Galactic disk. There are some reasons to believe that there may…

Astrophysics · Physics 2014-10-13 David Maurin , Richard Taillet

The single stable isotope of beryllium is a pure product of cosmic-ray spallation in the ISM. Assuming that the cosmic-rays are globally transported across the Galaxy, the beryllium production should be a widespread process and its…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. Smiljanic , L. Pasquini , P. Bonifacio , D. Galli , B. Barbuy , R. Gratton , S. Randich